So much focus on network security goes to keeping outsiders from getting in, but Derek Manky of Fortinet recently blogged about how the real threat to network security comes from inside the firewall. According to Manky, the five most common threats to the network are:

USB devices

Laptops and netbooks

Wireless access points

Smartphones and similar devices

E-mail

What do these things have in common? People within the company are using them for legitimate work reasons. Manky's recommendation for fixes is pretty straightforward, too: better encryption, enforced security policies and change the computer's autorun default whenever an external drive is plugged in.

Yes, some of you reading this are thinking, "We know this stuff already." But the "no-brainer" security precautions are often the first to fall by the wayside. After all, how many times have you plugged in a thumb drive that was grabbed from your kid's desk or clicked on a link without double-checking to make sure that it was secure?